Laser doping of solar cells

Eyecatcher LASSOLThe goal of the project is to demonstrate a significantly enhanced efficiency of silicon solar cells by selectively fabricating emitter structures with increased doping concentration using pulsed green laser radiation under industrial conditions. On wafers doped with low concentration in a furnace, locally highly doped structures shall be created which will enable to markedly improve the efficiency. This will lead to a significant reduction of the specific costs (in Euro per Watt) of the solar cells.

At the same time, the feasibility of full-area laser doping of solar cells will be investigated. This technique would allow to completely avoid the costly standard doping process in a continuous furnace and to replace it by a compact, energy saving laser doping machine which performs the full-area doping within one second. This laser doping would allow using thinner wafers which would save a considerable amount of raw material.

In contrast to other published structuring methods, the proposed laser doping process allows fabricating the selective emitter structure in just one process step and to keep all prior and subsequent process steps the same. This will lead to a very cost-efficient method that is easy to integrate in existing production lines.

The commercial potential of laser doping is enormous. In the case of success, the implementation of laser doping will safeguard and strengthen the position of the German solar cell manufacturers.


Dr. Andreas Voss
University Stuttgart, Institute for Beam Tools (IFSW)
Pfaffenwaldring 43
D-70569 Stuttgart / Germany
Tel. +49 (711) 685-66854
Fax +49 (711) 685-66842

Project partners

LIMO Lissotschenko Mikrooptik GmbH
Manz Automation AG
Schott Solar AG
Solarwatt Cells GmbH
Trumpf Laser GmbH & Co. KG
University Stuttgart, Institute for Physical Electronics
University Stuttgart, Institute for Beam Tools